The present invention relates to a lamp device for a vehicle, for example, a head lamp for a motor vehicle, a fog lamp for a motor vehicle or the like which lights a forward section of the motor vehicle. In particular, the invention relates to a lamp device for a vehicle in which a light distributing function is mainly given to a reflector side.
In a recent lamp device for a vehicle, a reflection surface of a reflector is formed in a free curves surface and a light distributing function is given to a side of the reflector. Further, in the recent lamp device for the vehicle, a so-called plain lens is used as a lens thereof and a function of an outer cover is given to a side of the lens. The plain lens corresponds to a lens in which a prism for light distribution is not formed and the light transmits as it is without being refracted. That is, the plain lens is constituted by a light transmitting member formed in a plate (a flat plate, a curved plate) shape such as a simple plate glass or the like.
However, in the conventional lamp device for the vehicle, the reflection surface of the internal reflector is clearly visible through the plain lens from an external section. Accordingly, it is necessary that the conventional lamp device for the vehicle is finished so as to have at least an optical performance required for reflection on a surface of the reflection surface of the reflector, and this working operation is troublesome.
Accordingly, the inventors of this invention have invented a lamp device for a vehicle in which an interior section is made hard to be visible in comparison with the plain lens (Japanese Patent Application No. 11-209331 (Japanese Patent Application Laid-Open No. 2001-35215).
It is an object of this invention to provide a lamp device for a vehicle in which a surface finishing process of a reflection surface in a reflector can be easily executed than the conventional one by making an interior section hard to be viewed in comparison with a plain lens.
In order to achieve the object, according to one aspect of the present invention, there is provided the lamp device for a vehicle wherein, a shape of a vertical cross section and a shape of a horizontal cross section in a lens are convex shapes.
As a result, in accordance with the invention, since the shape of the vertical cross section and the shape of the horizontal cross section in the lens have the convex shape, a light transmitting through the lens is largely reflected without a prism being formed, whereby the interior section becomes hard to be viewed. Accordingly, in accordance with the invention, it is not necessary to finish the surface of the reflection surface of the reflector so as to have an optical performance equal to or more than an optical performance required for reflection with taking an appearance into consideration, and the working operation can be easily executed in comparison with the conventional structure.
Other objects and features of this invention will become understood from the following description with reference to the accompanying drawings.